Star of "Smurfs," and most famously known as Barney in “How I met you Mother,” the charming Neil Patrick Harris couldn’t resist showing off his babies dressed up in their holiday outfits, including a very convincing pair of leprechauns. The beaming father showed off his snapped of Gideon and Harper on “The Late Show with David Letterman."

Harris (37) and his partner David Burtka (35) were ecstatic when the twins were born to a surrogate mother last August. “The Doogie Howser M.D.” actor revealed that his partner would not let Harris publicize their plan to have children until they had actually been born.

Speaking to Letterman, he said that he and Burtka cannot help dressing up the babies in costumes for each holiday. They included leprechauns for St. Patrick’s Day, little Mexicans for Cinqo de Mayo and bunny rabbits for Easter. -----------READ MORE: Neil Patrick Harris' profile page - Top Irish American

Currently the couple and the babies are in New York. Burtka told New York Magazine that they’ve been enjoying showing them around the city.

He said: “They’re enjoying New York; they’re able to wander more here than in LA. This is more of a walking town, so we’ve strapped on the Baby Björns plenty of times, and they like to see all that there is to see here."

Burtka, a chef and actor, has been staying at home with the babies. He said: “'I've been taking care of a lot of babies, as you know, so I spend a lot of my days doing that … They are the most fantastic kids …We have been blessed with two perfect little angels. Happy and sleeping, and it's a godsend. We’re thrilled."